page_title: Anatinae
section_title: History of classification
hierarchical_section_title: Anatinae / Systematics / History of classification
caption_attribution_description: English: Spot billed ducks dabbling
context_page_description: The Anatinae are a subfamily of the family Anatidae. Its surviving members are the dabbling ducks, which feed mainly at the surface rather than by diving. The other members of the Anatinae are the extinct moa-nalo, a young but highly apomorphic lineage derived from the dabbling ducks.
  There has been much debate about the systematical status and which ducks belong to the Anatinae. Some taxonomic authorities only include the dabbling ducks and their close relatives, the extinct moa-nalos. Alternatively, the Anatinae are considered to include most "ducks", and the dabbling ducks form a tribe Anatini within these. The classification as presented here more appropriately reflects the remaining uncertainty about the interrelationships of the major lineages of Anatidae.
context_section_description: Traditionally, most ducks were assigned to either the shelducks, the perching ducks, and the dabbling and diving ducks; the latter two were presumed to make up the Anatinae. However, the perching ducks turned out to be a paraphyletic assemblage of various tropical waterfowl that happened to evolve the ability to perch well in their forested habitat. Several of these, such as the Brazilian teal, were subsequently assigned to the Anatinae.
  As for the diving ducks, mtDNA cytochrome b and NADH dehydrogenase subunit 2 sequence data indicates that they are fairly distant from the dabbling ducks. The morphological similarities are due to convergent evolution.
  In addition, the genus Anas, as traditionally defined, is not monophyletic; several South American species belong to a distinct clade which would include the Tachyeres steamer-ducks. Other species, such as the Baikal teal, should also be considered distinct.
caption: Spot-billed ducks dabbling
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